.main{
    width:100%;
    height:1000px;
    font-family: '宋体';
    background-color: #fffff0;
    color:#333;
    line-height: 1.6;
    padding:5%;
    margin:0;
    display:flex;
    flex-direction: column;
    min-height: 0;
}

.letter{
    flex:1;
    display:flex;
    flex-direction: column;
    min-height: 10vh;
    overflow-y:auto;
    width:80%;
    max-width: 2000px;
    background-image:linear-gradient(#f3f3f3 1px, transparent 1px);
    background-size: 100px 24px;
    padding:0;
    position:relative;
}


.letter .head{
    margin-bottom:10%;
}

.letter .foot{
    text-align:right;
    outline:none;
    margin-bottom: 10%;
}

 .letter .date{
    margin-bottom: 10%;
}

.letter .content{
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    margin-left: 10%;
    outline:none;
    line-height:20px;
}
